The present invention relates to a glass pipe heat exchanger, particularly for cooling of hot smoke gases with aggressive components.
Heat exchangers of the above-mentioned general type are known in the art. The glass pipe heat exchangers with pipe bottoms and side walls of high corrosion-resistant steels, for example CrNi-steel with extremely high nickel content, are used in particular where smoke gas with extremely aggressive components must be cooled, whose chemical composition cannot be exactly determined in advance. The main field of application is garbage incinerating devices. They are also used for elimination of waste from the automobile industry. In both cases the chemical composition of the generated hot smoke gases are not known because of the constantly changing mixture of the materials to be burnt. The above-described glass pipe heat exchanger is charged with hot smoke gas through the glass pipes and guided at the exit via a washer with a subsequent droplet separator, whereas the glass pipes are loaded between the side walls and the bottom walls with cold clean gas. The clean gas which is thereby heated in the heat exchanger is finally supplied to the fire place. It has been noticed that despite all measures taken with respect to the gas passage and with respect to the material for the pipe bottoms and side walls, the side walls of the heat exchanger are subjected to corrosion after a relatively short operation time.
The cause of this is exceeding of the dew point in the region of the side walls, inasmuch as the side walls encounter exclusively the clean gas which is considerably cooler than the smoke gas. As a result, the aggressive components in gas come into their full action.